Pace Zone Index (PZI) introduction

The Training Peaks Pace Zone Index (PZI) was developed in conjunction with Matt Fitzgerald and will be featured in his upcoming book The Cutting Edge Runner. PZI represents a practical evolution of the principles developed by legendary running coach and author Jack Daniels. PZI is to runners what a handicap is to golfers. By simply looking up a recent 3k, 5k or 10k time in the chart, a runner can find their current PZI. The PZI numbers are set on a scale from 50-0 and provide a simple method of indicating current fitness levels for runners. The higher numbers indicate performance levels that can be achieved by beginning runners, while the lower numbers represent elite performances. Just as in golf, world record level performances are off the charts and would be represented by negative numbers. Each PZI is associated with 10 Individualized Training Zones. These zones can be used as handy reference points with conventional tools like stop watches and split times or they can be programmed into new devices like the Garmin GPS Forerunner 301. Each zone represents a range of pace used to achieve a specific training effect.

All race performances on the chart are listed in the format of minutes:seconds, while training paces are listed in the format of minutes:seconds/mile (a metric version is in the works). The lowest pace on the chart is set to 59:59. This represents the slowest value that registers on compatible devices like the Garmin Forerunner 301. Zones 1, 5, 7 & 9 are indicated as “Gray Zones” and represent various running paces that are not efficient for run training. Paces represented by these zones are either too slow or too fast to achieve desired training effects. Runners should avoid training for extended periods of time in Gray Zones.

Conversely, zones 2, 3, 4, 6, 8 &10 represent efficient training zones. Training in each of these zones produces a specific training effect. For instance zones 2-4 are most conducive to base training for aerobic endurance. Zone 6 correlates with Anaerobic Threshold (AT) or Tempo Training. Zone 8 represents the range of pace that will force the runner to operate at or near their VO2 Max. Finally, Zone 10 presents the runner with a range of paces that can be used for pure speed training. This zone is bound by a low end that should be achievable by athletes with the associated PZI. Zone 10 is topped off by a pace that loosely correlates with the world record for a 100 meter dash. This feature is designed to allow training devices to accommodate reasonable running scenarios without giving false out of zone readings.

Currently, the PZI chart assumes that you are training under conditions similar to those in which you achieved the performance used to identify your PZI. Extreme shifts in temperature or radically different footing will obviously affect your ability to train in paces that correlate correctly with your PZI. Similarly, running up and down hills will result in situations that make it difficult to prescribe proper intensity based on PZI. Training Peaks is actively working on Environmental Shift Factor™ and Altitude Normalized Pace™ algorithms to remedy these situations. We also plan to introduce calculators that will allow you to identify your PZI using performances at other distances ranging from the mile to the marathon. For now, we hope you enjoy this revolutionary approach to prescribing training intensity for running and, as always, we welcome your feedback.